CHECKING TENSION AND ADJUSTING
See Figures 1, 2, 3, 4, 5, 6, 7 and 8
Inspect your car's drive belts every 7,500 miles or six months for evidence of wear such as cracking, fraying, and incorrect tension. Replace the belts at a maximum of 30,000 miles, even if they still look acceptable.
You can determine belt tension at a point halfway between the pulleys by pressing on the belt with moderate thumb pressure. The amount of deflection should be in proportion to the length of the belt between pulleys (measured from the center of each pulley). For example, a belt stretched 13-16 in. (330-406mm) between pulleys should deflect 1 / 2 in. (13mm) at the halfway point; a belt stretched 7-10 in. (178-250mm) should deflect 1 / 4 in. (6mm), etc. If the deflection is found to be too little or too tight, an adjustment must be made.
Before adjusting any of your engine's drive belts, clean all mounting bolts on the component being adjusted and apply penetrating oil if necessary on those bolts which are hard to reach-which may be many if your car has a V8 with lots of power options. Loosen the mounting and adjusting bolts of whichever component (alternator, air pump, air conditioner compressor, power steering pump, etc.) you are adjusting. Pull outward, away from the engine, on the component until the belt seems tight. Temporarily snug up on the adjusting bolt and check belt deflection; if it is OK, tighten the mounting bolts and adjusting bolt.
To replace a belt, follow the above procedure for belt adjustment to the point of loosening the adjusting bolt. Push the component in towards the engine; this should give enough slack in the belt to remove it from the pulleys. Tighten the new belt in the normal manner.